iPhone 5 to get 4.6-inch screen? 4-inch more likely and here's why

Rumours of the new iPhone getting a bigger screen have surfaced on the internet once again, this time based on comments from an unnamed source talking to a Korean newspaper that Apple has chosen the larger display and has already begun ordering the parts from suppliers.

This time, rather than the new iPhone, dubbed the iPhone 5, featuring a 4-inch screen, the report claims Apple will launch a 4.6-inch screen instead, giving a diagonal size the same as the Galaxy Nexus. However, this would make the new iPhone very wide, to accomodate the 3:2 aspect of the display.

Certainly, Apple will be looking to maintain the "retina display" tag, so will want to keep the pixel density high with any increase in size. One of the concerns with increasing the size of the display or the resolution is making sure that all the apps will look good.

With the increase in resolution on the new iPad pushing lots of updates through for apps, Apple is potentially paving the way for a seamless move to a larger size.

But moving back to the new iPhone screen size rumours, we feel that 4 inches seems much more likely. Not only would this make for a more comfortable size in a 3:2 device, but the calculations work too.

Getting all geeky for two seconds, the current iPhone has a 960 x 640 pixel resolution giving it a pixel density of 326ppi.

A resolution of 1080 x 720 pixels, the close to the iPad 2, would mean a pixel density of 324ppi on a 4-inch screen, which is close enough to satisfy Apple's Retina display criteria. That's well within the realms of displays already out there and would fit with apps and be familiar to developers.

By contrast, a 4.6-inch device would need to be more like 1250 x 833 pixels to hit that 326ppi. It's not that this resolution of display is unheard of - it's certainly doable at the moment - but the width of the device would be impractical.

But whatever the final size and resolution, we can't help feeling that the increase in resolution on the new iPad will play a huge part in paving the way for a newer, bigger, iPhone 5.

With no confirmation from Apple on this, however, everything is hearsay and theory at the moment.

Stuart has been a tech journalist since 1998 and written for a number of publications around the world. Regularly turning up on television, radio and in newspapers, Stuart has played with virtually every gadget available.